Cleaning Up Nagios Core

I am running Nagios Core 3.4.3 on RHEL 5_x86 platform and am out of disk space. I was wondering if anyone has some information on how to recover some disk space. I can certainly virtualize this and give it more space, but I’d rather not at this time. I noticed there’s a folder labeled “groundwork” as well as a /tmp directory inside. I have been unable to locate any information on managing the Nagios Core system from a disk space management standpoint as everything keeps pointing to monitoring remote hosts. Thank you.